摘要:
Disclosed are polymers (polyaspartic acid Zwitterionic derivatives) containing, in the molecule, 1 mol % or more of at least one repeating unit selected from the group consisting of repeating units represented by the following formulas (1) and (2). ##STR1## These polymers are useful in the preparation of hair-treating compositions and cosmetic compositions having excellent hairdressing properties and good biocompatibility.
摘要:
A process is disclosed for producing with good productivity a cross-linked polyaspartic acid resin having biodegradability and high water absorbency. The process features inclusion of one of the following steps: (a) a polysuccinimide, which has been brought into a dispersed state by a dispersant, and a cross-linking agent are reacted to produce the cross-linked polyaspartic acid resin; (b) imide rings of a cross-linked polysuccinimide are subjected to a hydrolysis reaction while controlling a swelling degree of a resulting gel, whereby the cross-linked polyaspartic acid resin is produced; and (c) a gel of a cross-linked polysuccinimide, which has been obtained by reacting a cross-linking agent to a solution of a polysuccinimide in an organic solvent, is disintegrated to subject imide rings of the cross-linked polysuccinimide to a hydrolysis reaction, so that the cross-linked polyaspartic acid resin is produced. The process may also include one or both of the following steps as needed: (d) a gel of the cross-linked polyaspartic acid resin is washed with water and/or a water-miscible organic solvent; and (e) the polysuccinimide is produced using a basic amino acid as a cross-linking agent.
摘要:
A cross-linked polymer containing, in its molecule, recurring units represented by the following formula (1), and having biodegradability and high water-absorbency: ##STR1## wherein R.sub.1 is a pendant group having at least one functional group selected from the group consisting of acidic groups and salts thereof, a glycino group and salts thereof, cationic groups and betaine groups; X.sub.1 is NH, NR.sub.1 ', R.sub.1 ' being an alkyl, aralkyl or aryl group, O or S; and n.sub.1 is 1 or 2.
摘要:
A process is disclosed for producing with good productivity a cross-linked polyaspartic acid resin having biodegradability and high water absorbency. The process features inclusion of one of the following steps: (a) a polysuccinimide, which has been brought into a dispersed state by a dispersant, and a cross-linking agent are reacted to produce the cross-linked polyaspartic acid resin; (b) imide rings of a cross-linked polysuccinimide are subjected to a hydrolysis reaction while controlling a swelling degree of a resulting gel, whereby the cross-linked polyaspartic acid resin is produced; and (c) a gel of a cross-linked polysuccinimide, which has been obtained by reacting a cross-linking agent to a solution of a polysuccinimide in an organic solvent, is disintegrated to subject imide rings of the cross-linked polysuccinimide to a hydrolysis reaction, so that the cross-linked polyaspartic acid resin is produced. The process may also include one or both of the following steps as needed: (d) a gel of the cross-linked polyaspartic acid resin is washed with water and/or a water-miscible organic solvent; and (e) the polysuccinimide is produced using a basic amino acid as a cross-linking agent.
摘要:
The problem of the invention is to provide a novel biodegradable polymer without water solubility (hygroscopicity), but with moldability and excellent water disintegratability and biodegradability, a production method thereof, a molded product thereof and applications thereof. The biodegradable polymer of the invention is a biodegradable polymer having one or more imine bonds within a molecule, characterized in that the imine bond constitutes part of a main chain structure of the biodegradable polymer. The biodegradable polymer preferably comprises a biodegradable unit and an imine unit having one or more imine bonds and has a chemical structure, in which the biodegradable units are linked by the imine unit.
摘要:
The problem of the invention is to provide a novel biodegradable polymer without water solubility (hygroscopicity), but with moldability and excellent water disintegratability and biodegradability, a production method thereof, a molded product thereof and applications thereof. The biodegradable polymer of the invention is a biodegradable polymer having one or more imine bonds within a molecule, characterized in that the imine bond constitutes part of a main chain structure of the biodegradable polymer. The biodegradable polymer preferably comprises a biodegradable unit and an imine unit having one or more imine bonds and has a chemical structure, in which the biodegradable units are linked by the imine unit.
摘要:
A production process of high molecular weight polysuccinimide having a weight average molecular weight of 40,000 or higher is disclosed, which comprises the following steps: 1) mixing and heating aspartic acid and an acidic catalyst to produce a liquid, low molecular weight polymer mixture, 2) separating the acidic catalyst to appropriate extent from the liquid, low molecular weight polymer mixture, thereby directly changing a polymer-containing phase from a liquid phase into a solid phase to produce a solid, low molecular weight polymer mixture, and 3) conducting solid-state polymerization on the thus-obtained solid, low molecular weight polymer mixture. This process can be practiced in a simple apparatus, and is free of problems such as formation of a highly viscous phase, excessive formation of foam, and formation of a reaction mixture into coherent mass.
摘要:
A phase shift photomask for forming a fine-line pattern with high dimensional accuracy even at different focus positions. The phase shift photomask has a transparent substrate (1) of quartz, for example, and a light-shielding film (2) of chromium, for example, provided on the substrate (1). The light-shielding film (2) is partially removed to form a first opening pattern (4a) and a second opening pattern (4b) with a very small width which is annularly provided in a peripheral region adjacent to the first opening pattern (4a). The light-shielding film (2c) is left in each of the four corners of the second opening pattern (4b). In addition, a phase shifter layer 3 is provided over either of the first or second opening patterns (4a, 4b).